Panel for absorbing mechanical impact energy and method of manufacture

ABSTRACT

A panel for absorbing mechanical impact energy includes a substrate and a multiplicity of fibers attached, by one of their ends, to the substrate with their other ends extending away from the substrate. The panel may include a thin, porous covering layer that overlies the free ends of the fibers. The porosity of the cover and the fiber density of the fibers may allow for breathability of the panel. The panels may be flexible and may be used in body protection devices such as helmets, body armor as well as in other environments. Panels may be configured in a variety of energy absorbing arrangements for differing applications.

FIELD OF THE INVENTION

The invention relates to energy absorption panels for cushioningmechanical impact loads.

BACKGROUND

The need for energy absorbing padding to cushion mechanical impact loadsis present in many environments. For example, personal protectionequipment such as helmets, shin guards and body part protectorstypically include some form of cushioning layer. The type of helmetcommonly used in football, for example, has a hard outer shell thatgenerally is molded of impact resistant plastic such as acrylonitrilebutadiene styrene (ABS) or polycarbonate. The interior of the helmet islined with various components that may be formed, for example, fromvarious materials such as felt, fibrous knits, foam-padding materialsuch as ethylene vinyl acetate, vinyl nitrile or urethane/rubber. Theliner is included in the design of the helmet and functions to providesome cushioning of direct physical impacts during active play.

Other environments where high impact forces are present are thoseinvolving body armor. For example, bulletproof vests typically arefabricated from polyaramid (Kevlar®), polyolefin fibers, woven or matfabrics having high impact and cut resistance. When struck by aprojectile, these vests and similar clothing can impress a direct forceon the wearer's body area that, while potentially life-saving, can causesignificant bodily bruising and/or a bone fracturing injury.

It is desirable in these and in other environments where impact forcesare involved that the helmet or protective garment be comfortable and insome applications, that it has the ability to allow airflow between theuser's body and the helmet or protective garment. It also would bedesirable to provide a liner construction adapted for use in suchenvironments that is flexible, can be formed in various shapes, displaysan energy absorbing compression function, can be worn close to the bodyand may enable airflow between the body and the protective helmet orgarment.

SUMMARY

The invention provides panel constructions that may be relatively thin,flexible and may be used as direct impact absorbing devices or may beused in conjunction with other devices, such as the cushioning materialscommonly found in helmet padding and the like. In the context of thisinvention, the term panel refers to a flexible, planar member with avery small ratio of thickness to length and width. A panel, inaccordance with the invention, includes a substrate to which amultiplicity of short fibers are attached, by one of their ends, withthe other ends of the fibers extending away substantially perpendicularto the substrate. A porous protective covering layer of material mayoverlie the array of fibers to serve as a layer for the fibers. Theprotective covering layer may be attached to the substrate so that thefibers are wholly contained within the envelope. The fibers are arrangedon the substrate at a fiber density (fibers per unit area) in closeproximity to each other and are oriented in a direction generallyperpendicular to the surface to which they are attached. The fibers areresilient so that they may deform under the influence of an impact loadapplied to the panel, yet return or spring back substantially to theirpre-impact configuration. The collective effect of the multiplicity offibers is to provide a cushioning and reduce the transmitted impactforce by absorbing some of the applied impact load.

Although the fibers are arranged in close proximity, they neverthelessmay be so arranged to have a low enough fiber density (number of fibersper unit area) to allow airflow between the substrate and the porousprotective covering. Additionally, airflow holes may be formed, as byneedle punching, in any covering for the panels and/or the substrate tofacilitate breathability of the panel. Moreover, panels made inaccordance with the invention may be constructed and arranged to besufficiently flexible to conform to body contours and to internalcontours of other protective devices, such as helmets, body armor vestsand other body protection devices. The characteristics of the panel maybe varied by selection from among a variety of materials for thesubstrate, covering, fiber characteristics, fiber dimensions, fiberspatial densities and fiber geometrical arrangements.

In other aspects of the invention, two or more panels may be stacked toprovide multilayer arrangements with additional compressibility andvarying characteristics. Among the variations of the invention panelsmay be formed to be double-sided, that is, to have a central supportlayer with fibers projecting outwardly from each side of the supportlayer. The double-sided panels may be stacked (1) with the fibroussurfaces of each individual panel being separated by a layer of a fabricseparator sheet that prevents the facing fibrous layers of the panelassembly from becoming enmeshed with each other or (2) with noseparating layer so that the fibers of one panel become enmeshed withthe fibers of an adjacent panel. In yet another aspect of the inventionthe fibers of the panel are arranged so that when the panel is subjectedto an impact load the fibers collapse resiliently and, in doing so, mayfrictionally engage each other to enhance the energy absorptioncapability of the panel.

In a further aspect of the invention the fibers attached to one surfaceof the support ply may include a mixture of two or more groups offibers, including a group of longer, higher denier, relatively stiff,but resilient fibers and another group of shorter, lower denier fibersthat are relatively soft and less resilient with the fibers of thegroups being interspersed with each other.

In yet another aspect of the invention a method is provided formanufacturing panels having a mixture of two groups of fibers using aflocking process in which a support ply or substrate is coated, over itssurface, with an uncured, fluid adhesive. A first group of amultiplicity of short, low denier fibers is electrostatically propelledagainst the fluid adhesive coated surface whereby the fibers becomeembedded, at one of their ends, in the fluid adhesive with the otherends of the fibers extending freely away from the support. Before theadhesive has cured a second group of a multiplicity of fibers of higherdenier and greater length similarly is embedded in the adhesive usingthe previously described electrostatic flocking process. The adhesivethen is caused or is permitted to cure to securely attach the fibers tothe support.

DESCRIPTION OF THE DRAWINGS

The various aspects and advantages of the invention will be appreciatedmore fully from the following description of the invention inconjunction with the accompanying, not-to-scale, diagrammatic drawingsin which:

FIG. 1A is diagrammatic side view of a basic panel structure with theprotective cover separated from the panel;

FIG. 1B is diagrammatic side view of the basic panel structure of FIG.1A with the protective cover attached to the panel and covering thefibers;

FIG. 2 is a diagrammatic side view of the panel of FIG. 1B undercompression;

FIG. 3 is a diagrammatic side view of a double-sided panel;

FIG. 4 is a side view photograph of a double-sided panel of the typediagrammed in FIG. 3;

FIG. 5A is a diagrammatic side view of a panel construction of twopanels with a separator fabric between the two panels beforecompression;

FIG. 5B Is a diagrammatic side view of the multilayer panel constructionof FIG. 5A during compression;

FIG. 6A is a diagrammatic side view of a panel before compression by anirregularly shaped object;

FIG. 6B is a diagrammatic side view of the panel of FIG. 6A during thecompression by an irregularly shaped object;

FIG. 7 is a diagrammatic side view similar to FIG. 1A in which thesupport ply is formed to include a plurality of perforations tofacilitate airflow through the panel;

FIG. 8 is diagrammatic side view similar to FIG. 7 in which the fibersare depicted as being longer than those of FIG. 7;

FIG. 9 is a diagrammatic illustration of an embodiment in which thefibers are applied directly to a polymeric foam substrate;

FIG. 10 is a diagrammatic illustration of an embodiment in which a pairof panels are disposed face to face with the fibers of each of thepanels facing the support ply of the other of the panels and with thefibers of one panels being enmeshed with the fibers of the other panel;

FIG. 11 is a diagrammatic illustration similar to FIG. 3 in which thecentral support ply is provided with a plurality of perforations tofacilitate airflow through the panel;

FIG. 12 is a diagrammatic illustration similar to FIG. 11 in which thefibers are longer than those depicted in FIG. 11;

FIG. 13 is a diagrammatic illustration of a double-sided embodiment ofthe invention in which fibers having different characteristics of lengthand denier are attached to the central support ply;

FIG. 14 is a diagrammatic illustration of a three-panel embodiment ofthe invention including an inner, double-sided panel and a pair of outerpanels arranged with their fibers extending inwardly toward the centralsupport ply of the inner panel and with the fibers of the outer panelsbeing enmeshed with the fibers of the inner panel;

FIG. 15 is a graph showing compression versus load for rate conventionalfoam padding material as used in a hockey helmet; and

FIG. 16 is a graph showing compression versus load for a combinedlayered structure of the hockey helmet foam pad and a double-sided panelof FIGS. 3 and 4.

DETAILED DESCRIPTION

A basic panel structure 10 of the invention is illustrated in FIGS. 1Aand 1B and includes a substrate or support ply 12 having a multiplicityof fibers 14 attached, at one of their ends, to the support ply 12. Formost applications the support ply 12 preferably should be selected to beflexible so that it may conform to a contoured surface with which it maybe used and to which it may be applied. The degree of panel flexibilitywill be a function of the particular application. For example, a greaterdegree of flexibility for the support ply 12 may be desired when thepanel is to be used in a body garment than in a protective helmet. Byway of example only, the support ply may be formed from a variety offabrics such as woven, knitted or nonwoven fabrics. In some applicationsthe support ply may be formed from a layer of non-fabric material thatmay be more or less flexible than a fabric. In other applications a foammaterial could be used as the support ply. The support ply may be formedor cut to any peripheral shape to fit a particular application.

In the preferred method of practicing the invention, the fibers 14 areapplied to the support ply 12 by a flocking process in which a surfaceof the support ply 12 is coated with a curable fluid adhesive and a bythe electrostatic (flocking) process a multiplicity of fibers 14 arealigned in an electric field and propelled toward the electricallygrounded uncured adhesive coated substrate such that the ends of thefibers become embedded in the adhesive with the fibers being orientedgenerally perpendicular to the support ply 12. Details of the flockingprocess involve the electrostatic alignment of specifically cut, shortfibers, onto the fluid, uncured adhesive coated and electrostaticallygrounded fabric or flexible or rigid material substrate. This isaccomplished by impinging the electrostatically charged and aligned, inthe electric field, short fibers into the uncured adhesive on theelectrically grounded surface and then subsequently curing or allowingcuring of the adhesive, thus securing the electrostatically alignedfibers in place.

The flock density may be varied, in combination with the otherparameters of the fibers and other components, to achieve the panelcharacteristics desired for the particular application. One can vary theflock density by controlling the number of fibers applied to theadhesive coating. Additionally, applying the adhesive in patterns on thesubstrate so that fibers will attach only in an array defined by theadhesive pattern also may be employed to vary flock density. For examplethe adhesive may be may be applied in a dot pattern, square pattern,striped pattern or any other desired pattern.

To keep the fibers collectively together and to prevent the fibers frommicroscopically penetrating into an object to be protected, a contiguouslayer 16 of a thin, flexible fabric or perforated plastic sheet (such aspolyester film or Mylar) is applied over the fibers to envelop them. Thelayer 16 is secured to the substrate 12 as by sewing, adhesive bonding,or overall discrete adhesive coating or other suitable attachmentmethods.

The fibers 14 may be comprised of synthetic polymeric fibers of the typecommonly used in textile or flocking industries, such as, for example,nylon or polyethylene terephthalate (PET), although the characteristicsof the fibers should be selected so that they will have sufficientstiffness while providing a desired degree of resilience. By way ofexample, nylon 66 fibers or other fiber materials having sufficientmodulus of elasticity, when combined with the denier and length, toprovide the desired resilience and cushioning may be employed. Thefibers should be of relatively high denier, for example, in the range ofabout ten to about 60 denier and preferably in the range of about 20 to45 denier and may have a length, preferably in the range of about two(2) to about six (6) mm such that the combined characteristics of thefibers 14 result in a sufficiently stiff fiber that may present a degreeof springiness or resistance of an order of magnitude sufficient toabsorb impact energy from a mechanical compression load that can beanticipated for the particular application. In a preferred embodimentthe flock fibers should be applied to the substrate surface such thattheir coverage will have a fiber density (“flock density”) in the rangeof between about 50 to about 600 fibers/sq. mm.

FIG. 2 illustrates the behavior of the spring-like flock fibers 14 whena compression force is applied to a panel. FIG. 3 depicts the panel 22disposed on a base 20 and having compression force applied. FIG. 2demonstrates, diagrammatically, the manner in which the fibers bend,buckle, or otherwise deform, resiliently, under the influence of amechanical impact load. The energy absorbing function of the panel isdue in part to the spring action of the device as it absorbs energy. Inaddition to the spring action, the flock fibers are in proximity to eachother and, as they deform, may generate an inter-fiber friction force asthe fibers rub against each other dynamically during compressive impactdeformation.

FIG. 3 illustrates another embodiment of an energy-absorbing panel 50 inwhich fibers 54, 56 are attached to both sides of a central support ply52, respectively. As with the previously described embodiment, to keepthe flock surface arrangement collectively together and to prevent theflock fibers from microscopically penetrating into the object beingprotected, a contiguous layer of a thin flexible fabric or perforatedplastic sheet 60 is applied to envelop the flocked panels. The sheet 60is secured to the central support ply 52. The sheet or fabric 60 may beperforated, as by needle punching, to facilitate airflow through thepanel. The central support ply also may be perforated for the samepurpose. It should be noted that in the previously described embodimentsas well as in this and other embodiments the fibers, although positionedclose to each other, nevertheless they may provide sufficient open spaceto permit airflow through the panel. The ability for the panel to“breathe” may enhance the comfort to the user.

FIG. 4 is a magnified photograph of the double-sided panel showndiagrammatically in FIG. 3. The double-sided panel 60 includes thecentral support ply 72, a first plurality of fibers 74 attached to thecentral support ply and a second plurality of fibers attached to theother face of the central support ply.

FIGS. 5A and 5B are diagrammatic representations of an assembly of twopanels not compressed (100) and compressed (110), respectively. Thecomparison of FIGS. 5A and 5B demonstrates the manner in which the flockfibers bend, twist or curl under a compressive load.

FIGS. 6A and 6B demonstrate, diagrammatically, the ability of a panel inaccordance with the invention to respond to a compressive force from anuneven, compound hard surface 152. When the compound-shaped surface 152,engages the panel, the fibers in the convex zones of the surface bend,buckle, crush and conform to the shape of the convex surface. Thecompression force is conformably variably distributed. The flock fibersfacing the convex zones of the surface 152 are less deformed in thoseregions that are engaged by a concave or creviced portion of thesurface. Thus the degree to which the fibers may buckle is dependent onthe contour or shape of the object that imposes the impact load as wellas the contour of the object or body part being impact protected by thepanel. The energy is distributed along with the panel according to theshape of the impacting surface. When the load is removed, thespring-like characteristic of the fibers causes the panel to revert orre-bound toward its pre-impact configuration.

In each of the panels, the degree of breathability depends on the flockdensity (fibers per unit area) of the panel and/or the porosity of oneor both of the support ply 12 and the covering layer 16. The support ply12 of a panel as well as the cover (not shown in FIG. 7 or 8) of a panelcan be needle-punched, as suggested diagrammatically in FIGS. 7 and 8,to form a plurality of small airflow holes 19 that communicate with thefiber-containing space. Such needle punching also may increase theflexibility of the panels as may be desirable with impact garment liners(for example, sports clothing and armor shielding or bullet-proof vests,shoe insoles etc.).

Panels made in accordance with the invention may be used in conjunctionwith other shock absorbing members, for example, by attaching one ormore panels to a surface of a foam pad that either faces the user orfaces away from the user. In another embodiment, the fibers may beattached directly to a surface of a foam pad 114, as suggested in FIG.9. The foam may comprise any of the materials used for protectivepadding such as, for example, polyurethane memory foam, ethylene vinylacetate (EVA) foam, nitrile rubber foam, etc. Here, the foam layer mayserve as the substrate or supporting surface that may be coated withadhesive with the fibers then being attached as described above. Thefibers of the composite foam-fiber panel preferably are covered with athin, flexible fabric covering the ply presenting a comfortable surface,for example, terrycloth, micro-suede, flannel, etc.

FIG. 10 illustrates another embodiment of the invention in which twopanels 120, 122 are brought together with their flocked surfaces facingeach other such that the fibers of each of the panels face thesupporting substrate of the other of the panels. In this arrangement theopposed fibers of the panels will become enmeshed with each other whenthe panels are brought together (i.e., the fibers of one panel willextend in between and in engagement with the fibers of the other panel).The characteristics of the fibers (denier, lengths, flock densitiesshould be selected so that when the enmeshed fibers are subjected to animpact load the fibers of each panel will buckle as described above and,in doing so, will frictionally engage and interfere with each other toenhance the impact absorption capacity of the device. As with all otherembodiments of the invention, the fiber material, denier, lengths may beselected to result in an impact absorber having the desiredcharacteristics. Flock fibers of non-uniform length may be used in apanel and flock densities may be varied and placement and size ofperforations maybe varied. It should be understood that although FIG. 10illustrates one panel as having a foam substrate 124 and another panelhaving a thin substrate 126, the type and dimensions of the substratesmay be varied depending on the particular application in which theinvention is to be employed. It may be noted that although the fiberlengths in one of the panels 122 are shorter and thinner than thelengths and thickness of the fibers in the other panel 120, the fiberlengths for the panels may be the same or may be varied, again,depending on the desired energy absorption characteristics andapplication in which the invention is to be used.

Another variation that may be employed in configurations such as FIG. 10is that the covering panel may have a substrate 126 may be formed from amaterial or fabric that, although having fibers attached to an inwardlyfacing surface, presents an externally facing surface that is soft andcomfortable to the skin such as micro-suede. Terrycloth or othermaterial with a napped or soft velvet-like feel. FIG. 11 illustrates thetype of double-sided panel construction shown in FIGS. 3 and 4 in whichthe central support layer is provided with perforations 19 to facilitatethe breathability of the panel. FIG. 12 depicts an arrangement similarto FIG. 11 except that the fibers are greater in length. As describedabove, panels such as those depicted in FIGS. 11 and 12 preferably willbe covered by an outer, porous flexible ply that also may be soconfigured to include airflow perforations.

FIG. 13 illustrates, diagrammatically, an embodiment of a panel in whichtwo different fiber lengths and deniers are projecting from a surface ofa support ply. In this embodiment a number of the fibers 130 extendingfrom each face of the central support ply are of a heavier denier andare longer than other of the fibers 132 that are of lesser denier andare shorter. It is believed that although the relatively soft, lowerdenier, shorter fibers would, by themselves, present relatively lowenergy absorption characteristics, when combined with the higher denier,longer fibers, their combination presents greater energy absorptioncapability than either alone. As mentioned above, this is believed toresult from frictional interaction between the shorter/softer andlonger/stiffer fibers. Preferably the higher denier fibers may beapproximately twice the length of the lower denier fibers. Although inthe example discussed, the shorter fibers were of the order 0.028 incheslong, three denier, and the longer fibers were approximately 0.060inches long and 45 denier, it should be understood that the fiberarrangement may differ from this example by varying the lengths anddeniers, FIG. 13 being merely for illustrative purposes.

In some applications it may be desirable to mix fibers having differentlengths and deniers. For example, we have fabricated a composite ofthree double-sided panels, each individual panel is about four mm thick(total stacked thickness 12 mm) having a mixture of short, soft nylon 66fibers, 3.0 denier, 0.028″ in length and long, stiffer fibers, 45denier, 0.060″ long nylon fibers with the total assembly having an arealdensity of about 1.4 Kilograms/square meter. The construction of theseindividual panels is illustrated, diagrammatically in FIG. 13. They werefabricated by first coating one side of the central support ply withadhesive and then applying under an electrostatic field the shorter,softer fibers to the adhesive surface as described above. Then, beforethe adhesive layer containing these shorter softer flexible fibers wascured, the longer, stiffer fibers were then applied under the influenceof an electrostatic field, and were embedded in the adhesive,interspersed between the shorter, softer flexible fibers. The processthen was repeated on the other side of the central support ply,resulting in a double-sided panel. The panels were stacked, with a thinflexible polyester woven separator fabric placed between adjacent panelsto prevent the facing fibers of adjacent panels to extend into and meshwith each other. A thin, flexible micro-suede surfaced polyester fabricto retain the panels together then was placed about the stack of threepanels to envelop the stack. We found this arrangement of stacked panelsto absorb energy in a ball drop test comparable to a commerciallyavailable polyurethane memory foam (Poron® XRD, 9.5 mm thick) used inequipment such as helmets and the like. In this comparison, Poron® XRDmemory foam had an areal density of 1.8 Kilograms per square meter.While the Poron® foam and the panels described above had the sameball-drop test energy absorption performance the panel was over 20%lighter in weight than the foam. Therefore, the energy absorbing panelmaterial should have an important weight advantage over certain foammaterials in various applications. The areal density of an energyabsorbing material is an important consideration for sport and militarywear. It is believed that as the longer, springier and resilient fibersbuckle and deform under the influence of an impact load, they willinternally engage, frictionally, with each other and with the shorter,lower denier fibers to contribute to the ability of the panel to absorbsome of the impact energy.

FIG. 14 illustrates another embodiment that incorporates three panelsincluding a double-sided inner panel 140 having fibers 142 extendingfrom each surface of a central support ply 144 and a pair of outerpanels 150 each comprising a support ply 152 and a plurality of fibers154 extending inwardly toward the central support ply 144 of the innerpanel 140 and enmeshed with the fibers 142 of the inner panel 140. Whenthe device is subjected to a mechanical impact load the panels will becompressed causing the fibers to resiliently buckle and deform with thefibers of the panels frictionally engaging with each other as describedabove. In this embodiment the three-panel assembly may be enclosed in anenvelope, as of a thin polyester fabric, micro-suede, pile fabric or avelvet-like fabric. Alternatively, in this case, the outer supportingsubstrate material 152 could itself be fabricated from soft fabricswhere the outer side of the enveloping fabric is the soft-to-the-feelsurface and the inwardly facing side of the substrate 152 has theinward-projecting flock fibers 154. In other embodiments, one or both ofthe support plies of the outer panels may be formed from variousmaterials, depending on the application, such as a flocked foammaterial.

FIG. 15 is a graph 200 illustrating the force of an initial impact shockfor foam padding of the type used in a conventional hockey helmet. Thegraph plots the load, in KGF versus the compressional strain of thematerial in millimeters. As is apparent from the curve, there is a sharpknee in the curve at about 40 KG have and the current increasesexponentially thereafter. At a 50 KGF compressive load, 4 mm compressionin the material was observed. FIG. 16 shows a similar graph to FIG. 15for the same hockey helmet foam material to which a double-sided pad,such as that shown in FIGS. 3 and 4, was layered against the hockeyhelmet foam of FIG. 15. FIG. 16 demonstrates that the knee of the curveis significantly less pronounced which illustrates how the panel of theinvention blunts and effectively cushions the initial shock that ahockey helmet wearer would receive if the wearer's helmet were outfittedwith supplemental panels in accordance with the present invention. Inthis arrangement, approximately 8 mm of compression is observed at acompression force level of 50 KGF, signifying a more gentle impactabsorption obtained with the invention.

From the foregoing it will be appreciated that the invention provides anew type of energy absorbing padding material described as panels andpanel configurations and constructions adapted to cushion or bluntmechanical impact loads. Depending on the application, panels inaccordance with the invention may be used by themselves as a primaryprotective element or in conjunction with other energy absorbingdevices. The panels may be used individually or in combination withother energy absorbing layered materials to achieve the desired energyabsorption properties. The panels may be of lightweight, non-bulkyconstruction suitable for use in protective garments or sportsequipment. The panels are lightweight and are easily manufactured at lowcost. In addition to the impact absorbing features of the invention, thepanels can breathe and enhance user comfort. The principles of theinvention may be incorporated in various combinations of support plyconfigurations. The energy absorbing fibers serve as tiny spring-likespacer elements. In order to enhance the frictional characteristics ofthe fibers they may be treated with a friction-enhancing sizing. Theinvention may be practiced in a single or multilayer sandwichconfiguration with the fibers separating the plies and covering theelements of the sandwich.

It should be understood, however, that the foregoing description of theinvention is intended to be merely illustrative thereof and that otherembodiments, modifications and equivalents may be apparent to thoseskilled in the art without departing from the principles of theinvention.

We claim:
 1. A panel construction for absorbing energy from an impactload comprising: a substrate; a multiplicity of flocked monofilamentflock fibers, each having first and second ends, the fibers beingattached, at their first ends to a surface of the substrate with thesecond ends of the multiplicity of monofilament flock fibers extendingaway from the substrate; the multiplicity of monofilament flock fibersextending away substantially perpendicular to the substrate; themultiplicity of monofilament flock fibers being of a denier and lengthand being closely spaced to each other sufficiently to buckleresiliently and absorb a portion of the energy imparted to the panel byan impact load; and a thin flexible, porous, fabric, protective coverattached to the substrate and overlying the multiplicity of monofilamentfibers and unsecured from the free second ends of the multiplicity ofmonofilament flock fibers.
 2. The panel as defined in claim 1 whereinthe fibers have a denier in the range of about 10 to about
 60. 3. Thepanel as defined in claim 2 wherein the flock density of the fibers isin the range of about 50 to 600 fibers per square millimeter.
 4. Thepanel as defined in claim 1 wherein the fibers are between about 2 mm toabout 6 mm in length.
 5. The panel as defined in claim 4 wherein thefibers have a denier in the range of about 10 to about
 60. 6. The panelas defined in claim 5 wherein the flock density of the fibers is in therange of about 50 to 600 fibers per square millimeter.
 7. The panel asdefined in claim 4 wherein the flock density of the fibers is in therange of about 50 to 600 fibers per square millimeter.
 8. The panel asdefined in claim 1 wherein the panel is sufficiently flexible to conformor bend to varying contours.
 9. The panel as defined in claim 1 whereinthe spacing between the fibers enables air to flow between the substrateand the thin flexible, porous, fabric, protective cover.
 10. The panelas defined in claim 9 further comprising at least one of the substrateand the thin flexible, porous, fabric, protective cover being porous topermit airflow therethrough.
 11. The panel as defined in claim 1 whereinthe multiplicity of monofilament fibers are flocked onto the substratein a flock density so that they will frictionally engage adjacent onesof the multiplicity of monofilament fibers when deforming in response toan applied impact load wherein the frictional engagement increases theability of the panel to absorb a portion of an impact force.
 12. Thepanel as defined in claim 1 further comprising a second multiplicity ofmonofilament fibers attached to an opposite surface of the substrate.13. The panel as defined in claim 1 wherein the fibers are of differentlengths.
 14. The panel as defined in claim 1 wherein the fibers are ofdifferent deniers.
 15. The panel as defined in claim 1 wherein thesubstrate is formed from material adapted to absorb impact energy froman external impact force.
 16. The panel as defined in claim 15 whereinthe substrate comprises compressible foam.
 17. The panel as defined inclaim 1 further comprising: a second multiplicity of flockedmonofilament fibers each having first and second ends, the fibers beingattached, at their first ends to a second surface of the substrateopposite the surface of the substrate, with the second ends of thefibers extending away from the substrate; the second multiplicity offlocked monofilament fibers being of a denier and length and beingclosely spaced to each other sufficiently to buckle resiliently andabsorb a portion of the energy imparted to the panel by an impact load;wherein the thin flexible porous, fabric, protective cover furtherenvelops the second multiplicity of monofilament fibers and is attachedto the substrate with one of: adhesive bonding; and sewing; and aplurality of airflow holes formed by needle punching the flocked panelincluding the attached multiplicity of monofilament fibers and attachedsecond multiplicity of monofilament fibers; and wherein the thinflexible protective cover comprises one of: a polyester film; aperforated polyester film; a fabric; and a porous fabric.
 18. The panelas defined in claim 1, wherein the multiplicity of monofilament flockfibers further comprises: a first group of fibers, each fiber having arelatively high denier and fiber length and a second group of fibers,each fiber having a lower denier and shorter length than the fibers ofthe first group; and wherein the second group of fibers are interspersedamong the first group of fibers.
 19. The panel as defined in claim 18wherein the fibers in the first group have a denier of between about 10and 60 and a length of between about 2 mm to about 6 mm; and wherein thefibers in the second group have a denier between about 1.5 to about 9and a length of between about 0.5 mm to about 2.0 mm.
 20. The panel asdefined in claim 19 wherein the fibers in the second group are about 3.0denier and about 0.028 inch long and the fibers in the first group areabout 45 denier and about 0.060 inch long.